Designing Calcium Silicate Cements with On-Demand Properties for Precision Endodontics

Calcium silicate (C3S) cements are available in kits that do not account for patients' specific needs or clinicians' preferences regarding setting time, radiopacity, mechanical, and handling properties. Moreover, slight variations in powder components and liquid content affect cement's properties and bioactivity. Unfortunately, it is virtually impossible to optimize several cement properties simultaneously via the traditional "one variable at a time" strategy, as inputs often induce trade-offs in properties (e.g., a higher water-to-powder ratio [W/P] increases flowability but decreases mechanical properties). Herein, we used Taguchi's methods and genetic algorithms (GAs) to simultaneously analyze the effect of multiple inputs (e.g., powder composition, radiopacifier concentration, and W/P) on setting time, pH, flowability, diametral tensile strength, and radiopacity, as well as prescribe recipes to produce cements with predicted properties. The properties of cements designed with GAs were experimentally tested, and the results matched the predictions. Finally, we show that the cements increased the genetic expression of odonto/osteogenic genes, alkaline phosphatase activity, and mineralization potential of dental pulp stem cells. Hence, GAs can produce cements with tailor-made properties and differentiation potential for personalized endodontic treatment.

Myostatin knockout induces apoptosis in human cervical cancer cells via elevated reactive oxygen species generation

Myostatin (Mstn) is postulated to be a key determinant of muscle loss and cachexia in cancer. However, no experimental evidence supports a role for Mstn in cancer, particularly in regulating the survival and growth of cancer cells. In this study, we showed that the expression of Mstn was significantly increased in different tumor tissues and human cancer cells. Mstn knockdown inhibited the proliferation of cancer cells. A knockout (KO) of Mstn created by clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas) 9 (CRISPR/Cas9) induced mitochondria-dependent apoptosis in HeLa cells. Furthermore, KO of Mstn reduced the lipid content. Molecular analyses demonstrated that the expression levels of fatty acid oxidation-related genes were upregulated and then increased rate of fatty acid oxidation. Mstn deficiency-induced apoptosis took place along with generation of reactive oxygen species (ROS) and elevated fatty acid oxidation, which may play a role in triggering mitochondrial membrane depolarization, the release of cytochrome c (Cyt-c), and caspase activation. Importantly, apoptosis induced by Mstn KO was partially rescued by antioxidants and etomoxir, thereby suggesting that the increased level of ROS was functionally involved in mediating apoptosis. Overall, our findings demonstrate a novel function of Mstn in regulating mitochondrial metabolism and apoptosis within cancer cells. Hence, inhibiting the production and function of Mstn may be an effective therapeutic intervention during cancer progression and muscle loss in cachexia.

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Mstn is expressed in different tumor tissues and human cancer cells.

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Mstn knockdown inhibits the proliferation of cancer cells.

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Mstn KO induces mitochondria-dependent apoptosis in HeLa cells.

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Mstn KO increases the rate of fatty acid oxidation.

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ROS generation induces apoptosis in HeLa/Mstn KO cells.

PKM2 knockdown influences SREBP activation and lipid synthesis in bovine mammary-gland epithelial MAC-T cells

OBJECTIVE

The purpose of the article is to evaluate the changes in lipid metabolism in bovine mammary-gland epithelial MAC-T cells after PKM2 knockdown.

RESULTS

MAC-T cells stably expressing low levels of PKM2 were established with lentivirus-mediated small hairpin RNA. Although the knockdown of PKM2 had no effect on MAC-T cell growth, the reduced expression of PKM2 attenuated the mRNA and protein expression of key enzymes involved in sterol synthesis through the SREBP pathway.

CONCLUSIONS

The downregulation of PKM2 significantly influenced lipid synthesis in bovine mammary-gland epithelial MAC-T cells. These findings extend our understanding of the crosstalk between glycolysis and lipid metabolism in bovine mammary-gland epithelial cells.

Characterization and anti-inflammation role of swine IFITM3 gene

IFITM3 is involved in cell adhesion, apoptosis, immune, and antivirus activity. Furthermore, IFITM3 gene has been considered as a preferential marker for inflammatory diseases, and positive correlation to pathological grades. Therefore, we assumed that IFITM3 was regulated by different signal pathways. To better understand IFITM3 function in inflammatory response, we cloned swine IFITM3 gene, and detected IFITM3 distribution in tissues, as well as characterized this gene. Results indicated that the length of swine IFITM3 gene was 438 bp, encoding 145 amino acids. IFITM3 gene expression abundance was higher in spleen and lungs. Moreover, we next constructed the eukaryotic expression vector PBIFM3 and transfected into PK15 cells, finally obtained swine IFITM3 gene stable expression cell line. Meanwhile, we explored the effects of LPS on swine IFITM3 expression. Results showed that LPS increased IFITM3 mRNA abundance and exhibited time-dependent effect for LPS treatment. To further demonstrate the mechanism that IFITM3 regulated type I IFNs production, we also detected the important molecules expression of TLR4 signaling pathway. In transfected and non-transfected IFITM3 PK15 cells, LPS exacerbated the relative expression of TLR4-NFκB signaling molecules. However, the IFITM3 overexpression suppressed the inflammatory development of PK15 cells. In conclusion, these data indicated that the overexpression of swine IFITM3 could decrease the inflammatory response through TLR4 signaling pathway, and participate in type I interferon production. These findings may lead to an improved understanding of the biological function of IFITM3 in inflammation.

AMFR gene silencing inhibits the differentiation of porcine preadipocytes

Our study clarifies the role of the autocrine motility factor receptor (AMFR) gene in porcine preadipocyte differentiation. AMFR-siRNA was transfected into porcine preadipocytes and the preadipocytes were induced to differentiation. Subsequently, qRT-PCR was conducted to examine changes in mRNA expression of a series of genes in porcine preadipocytes, including AMFR, sterol-regulatory element-binding protein-1a (SREBP1a), SREBP2, insulin-induced gene 1 (Insig1), and Insig2. Expression changes in the mRNA of genes regulating adipocyte differentiation were also analyzed using qRT-PCR, including peroxisome proliferator-activated receptor gamma (PPARγ), CCAAT/enhancer-binding protein alpha (C/EBPα), and Kruppel-like factor 2 (KLF2). Western blot analysis was conducted to examine the changes in AMFR protein expression in porcine preadipocytes. Additionally, morphological changes in differentiated porcine preadipocytes were examined by oil red O staining, and changes in optical density (OD) values were measured using an ultraviolet spectrophotometer. At 24 h after transfection with AMFR-siRNA, AMFR mRNA expression significantly reduced (P < 0.01), and AMFR protein expression markedly decreased (P < 0.05). The mRNA expression of SREBP1a, SREBP2, Insig1, and C/EBPα was significantly reduced (P < 0.01), whereas the expression of KLF2 mRNA was significantly elevated (P < 0.01). After induction of preadipocyte differentiation, the number of lipid droplets decreased in the AMFR-silenced group, and the OD value markedly reduced (P < 0.05). In addition, the expression of C/EBPα mRNA significantly decreased (P < 0.05), whereas the expression of KLF2 mRNA considerably increased (P < 0.05). Taken together, silencing of the AMFR gene inhibits the differentiation of porcine preadipocytes.

Cloning and prokaryotic expression of the porcine lipasin gene

Lipasin has recently been demonstrated to be involved in lipid metabolism. In this study, two specific primers were used to amplify the lipasin open reading frame from porcine liver tissue. The polymerase chain reaction product was cloned to a pGEM®-T Easy Vector, digested by SalI and NotI, and sequenced. The lipasin fragment was then cloned to a pET21(b) vector and digested by the same restriction enzyme. The recombinant plasmid was transferred to Escherichia coli (BL21), and the lipasin protein was induced with isopropyl-β-D-thiogalactopyranoside. The protein obtained was identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis and western blotting. A pET-lipasin prokaryotic recombinant expression vector was successfully constructed, and a 25.2-kDa protein was obtained. This study provides a basis for further research on the biological function of porcine lipasin.

Expression of the porcine lipoic acid synthase (LIAS) gene in Escherichia coli

Lipoic acid synthase, which exists primarily in mitochondria, participates in the biosynthesis of intrinsic lipoic acid. The lipoic acid synthase gene in pig is known as LIAS. To further investigate the biological functions of the protein that is encoded by LIAS, we cloned the open read frame of porcine LIAS (GenBank No. JN797612.1) into the expression vector pET-28α(+). The resulting pET-28α(+)-Lias recombinant vector was introduced into the Escherichia coli BL21 (DE3) strain. With induction by isopropyl β-D-1-thiogalactopyranoside, the recombinant E. coli strain can express the target protein that has a molecular weight of 41.58 kDa, which was confirmed by Western blotting.

Effects of lipopolysaccharide on the stearoyl-coenzyme A desaturase mRNA level in bovine primary hepatic cells

This study aimed to compare the effects of lipopolysaccharide (LPS) on stearoyl-coenzyme A desaturase (SCD) gene expression in mouse primary hepatic cells. To obtain sufficient total RNA, primary hepatic cells were plated on 6-cm diameter-type collagen 1-coated dishes (1 x 106 cells per dish). The test was divided into 6 groups with 6 replications per group. The 6 groups were treated with the following volumes of LPS (0.1 mg/mL): 0, 1, 1.5, 2, 4, and 8 μL. The cells were cultured for 24 h, and the total RNA was extracted from samples. Reverse transcription polymerase chain reaction was used to analyze SCD mRNA levels. With increasing LPS amounts, the SCD mRNA expression first decreased and then increased slightly; the expression was the lowest in the 2-μL LPS condition. The SCD mRNA levels from the 4- and 8-μL LPS conditions were slightly higher than that from the 2-μL LPS condition, but the difference was not significant (P > 0.05). The SCD mRNA level from the 2-μL LPS condition was obviously lower than that from the 0-, 1-, and 1.5-μL LPS condition, and the differences were significant (P < 0.05), and the SCD mRNA levels from the 0-, 1-, and 1.5-μL LPS conditions were not significantly different (P > 0.05). The SCD mRNA levels from the 4- and 8-μL LPS conditions were obviously lower than those from the 0- and 1-μL LPS conditions, and the differences were significant (P < 0.05).

Molecular cloning and expression of the porcine S14R gene in Escherichia coli

We amplified S14R protein gene cDNA of porcine, cloned it into a prokaryotic expression plasmid, and expressed it in Escherichia coli. A pair of primers was designed based on the cDNA sequence of the porcine S14R gene in GenBank. The target gene fragment from porcine liver tissue was amplified by RT-PCR. Confirmed by auto-sequencing, the target gene fragment was subcloned into an expression vector of pET28a. The pET28a-S14R construct was subsequently transformed into E. coli BL21 (DE3). This construct was verified by restriction endonuclease digestion and sequencing. Using isopropyl β-D-1-thiogalactopyranoside induction, a new recombinant protein with the expected relative molecular mass of 24 kDa appeared. The result was identified by SDS-PAGE electrophoresis. Porcine S14R includes 549bp (GenBank No. JN793537), with an open reading frame of 549 bp coding 182 amino acids.

mRNA abundance and expression of SLC27A, ACC, SCD, FADS, LPIN, INSIG, and PPARGC1 gene isoforms in mouse mammary glands during the lactation cycle

The functions of distinct isoforms of solute carrier family 27 transporters (SLC27A1-6), acetyl-CoA carboxylase (ACACA, ACACB), stearoyl-CoA desaturase (SCD1-4), fatty acid desaturase (FADS1-3), LPIN (LPIN1-3), insulin-induced gene (INSIG1, 2), and peroxisome proliferator-activated receptor gamma coactivator1 (PPARGC1A, B) were studied in the mouse mammary gland from pregnancy to lactation. The relative mRNA abundance and percent change in real-time PCR were determined. mRNA expression of SLC27A3 and SLC27A4 was 37- and 1.4-fold more upregulated at 12 days of lactation, respectively (P < 0.01). Transcripts of SCD isoforms were the most abundant, accounting for 59% of all genes measured, and PPARGC1 isoforms were the least (0.06% of all genes measured). The mRNA abundance from ACC, FADS and LPIN accounted for 29, 9 and 2.6%, respectively. INSIG1 mRNA expression was 32-fold more upregulated (P < 0.05), while PPARGC1B was 0.18-fold downregulated at 18 days of lactation (P < 0.01). We concluded that mRNA abundance and expression of these isoforms are affected by the stage of lactation.

Selection and use of reference genes in mouse mammary glands

Obtaining quantitative data concerning gene expression is important for understanding milk synthesis in mammary glands. Quantitative real-time PCR (qRT-PCR) is an efficient tool to calculate gene expression; however, it is necessary to find valid reference genes for normalization of qRT-PCR data. We applied the geNorm software to eight commonly used reference genes to identify the most stable and optimal genes for the mouse mammary gland. Based on this analysis, HPRT, RPL and GAPDH are the most appropriate reference genes for data normalization. We tested the expression of the alpha-lactalbumin and fatty acid synthase genes using these three reference genes, both normalized and non-normalized. The normalized mRNA expression ratio was significantly different from the non-normalized ratio. We recommend the use of these three reference genes for the normalization of qRT-PCR data in gene expression studies of mouse mammary glands.

[Analysis of 59 cases of non-traumatic sudden death in various neurological diseases]

Sudden death is a common complication of myocardial infarction, necrotic pancreatitis and other diseases. Physicians usually neglect the possibility of neurological disorders. 59 cases of sudden death among 314 autopsied cases with neurological diseases were analyzed. The most frequent cause of neurological sudden death was cerebrovascular disease (CVD). It was present in 53 (89.9%) cases. 48 of them had hemorrhagic CVD. 37 of these 48 cases were due to hypothalamic lesions. In 37 cases general autopsy was performed; pathological abnormalities of heart, lungs, stomach etc, were found in 28 of them. In conclusion, the size and location of the lesion correlated with the prognosis of the disease. Concomitant multiple organ damage may deteriorate the lesion. Awareness of sudden death resulting from CVD may elevate the rate of correct diagnosis.